Multi-sectional modular energy absorber and method for configuring same

ABSTRACT

A multi-sectional, modular energy absorber  10  comprising one or more modules, which have one or more energy absorbing units  12 . Some have a first section  14  and a second section  16  that are united like a clamshell to form the energy absorbing unit  12 . There is a means for locating the sections  18  in relation to each other. First and second flange sections  20,22  extend from at least some of the first and second sections. There are means for coordinating energy absorbing units  24  in one of the one or more modules, the means for coordinating  24  having a topography including a number (n) of apertures  26  defined therein, where n is an integer ≧0. At least some of the sections include an upper perimeter  28 , a lower perimeter  30  and an intermediate wall  32  extending therebetween with a number (m) of breaches defined in the intermediate wall before impact, where m is an integer ≧0.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to vehicle occupant safety during a collision,and more specifically to a multi-sectional “customized” or “tunable”multi-sectional energy absorber that absorbs energy imparted by anincident object that impacts the absorber, and a method for configuringthe absorber.

2. Background Art

Bumpers provide protection to pedestrians as well as occupants duringcollisions. Designed to absorb and deliver momentum when a vehicle is inan accident, bumpers are provided with designed components. Whenassembled, the components form a bumper system that is usually mountedon the front and rear of the vehicle. Often built with “crumple zones”,bumpers traditionally include designs that enable a specific bumper partto flex during collisions.

It is desirable for the bumper system to absorb as much impact energy inas little crush distance as possible, with as little weight as possible,yet be capable of being designed and manufactured under favorableeconomic conditions.

Generally, one or more energy absorbers are positioned between a vehicleoccupant and an incident force. In low speed impacts, the absorberserves to minimize damage to the fascia, lamps, and other components. Inhigh speed impacts, the absorber serves to protect occupants andpedestrians from injury.

Conventionally, an energy absorber can be manufactured at relatively lowcost by thermoforming and impact performance can be optimized withoutexpensive tooling modification at heights below about 50 millimeters.However, above this height, the base material thickness required toproduce an energy absorber for the appropriate crush resistance is suchthat it cannot easily and inexpensively be produced using in-linethermoforming equipment. In such circumstances, injection moldedabsorbers can be produced, perhaps at a lower cost.

A search that preceded the filing of this application revealed thefollowing U.S. references: U.S. Pat. Nos. 6,938,936 B2; 6,926,321 B2;6,923,495; 6,863,322 B2; 6,848,730; 6,749,784; 6,746,061 B1; 6,726,262B2; 6,669,251 B2; 6,550,850; 6,443,513 B1; 6,406,081 B1; 6,247,745 B1;6,199,937; 5,150,935; 4,597,601; 4,072,334; US 2003/0080573 A1; US2004/0036302 A1; US 2004/0094977 A1; US 2004/0174025 A1; US 2005/0057053A1; US 2005/0230204 A1; US 2005/0230205 A1; US 2005/0269824 A1; and US2006/0028038 A1.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a more cost effective,efficient multi-sectional energy absorber that can be “customized” or“tuned” to produce predefined energy absorption characteristics withinspatial constraints that may be imposed by a particular application.

The invention includes a multi-sectional modular energy absorber withone or more energy absorbing modules that are provided with one or moreenergy absorbing units therewithin. As used herein the term “energyabsorbing module” means an assembly of energy absorbing units that areunited by a common means for coordinating the units. At least some ofthe modules have one or more multi-sectional energy absorbing units. Inone embodiment, a first section and a second section unite to form agiven energy absorbing unit. Preferably, these sections are located inrelation to each other by means for locating the sections, such as ahinge, clips, glue, inter-engaging male-female members, dovetails,welding, pins, and combinations thereof, and the like.

One preferred (but not exclusive) method of manufacturing isthermoforming. It is known that thermoforming involves stretching aheated plastic sheet of constant thickness over a tool in the shape ofthe desired part. The stretching step results in a thinning of the sheetand ultimately in a non-uniform thickness distribution within the partmay result. Such problems are addressed by the invention. In oneembodiment, the first and second sections extend from the leaves of aliving hinge region that is positioned therebetween. In that embodiment,the sections and hinge cooperate like a clamshell. They emerge from athermoforming tool, for example, in an open position. (See, FIG. 9). Inuse, the two sections can be united about the hinge region to form theenergy absorbing unit.

The means for coordinating is terminated by a continuous periphery sothat within the periphery, the means for coordinating may be planar,curved, or curvilinear. The coordinating means has a topography with avariable number (n) of apertures, where n is an integer ≧0. The meansfor coordinating alternatively includes a web, a tether, a hinge, aplanar or curved surface, and wings or combinations thereof that serveto position and support the energy absorbing units in relation to eachother before, during and after relative motion between an incidentobject and the energy absorber. Impact between the energy absorbingunits and the incident object results in forces that are at leastpartially absorbed by the sections and common wall therebetween so thata blow imparted to a vehicle and its occupant(s) or pedestrians iscushioned.

In one embodiment, the two sections of the energy absorbing units (e.g.the clamshell in a closed configuration) have an upper perimeter, alower perimeter, and an intermediate crushable wall extendingtherebetween. Either the upper or lower perimeters can be presented tothe impacting force.

The energy absorbing units at least partially collapse during energyabsorption to a crushed configuration which in part is determined by theprovision of a number (m) of breaches that are defined in the wall of aunit before impact, where m is an integer ≧0. The breaches may bedefined by slits (no material removed) or slots (material removed toform an opening), or both. Thus, within a given multi-sectional energyabsorbing module, the means for coordinating may or may not be flat; mayor may not have a number (n) of apertures; one or more of the sectionsin the energy absorbing units in a given module may be provided with anumber (m) of breaches (e.g. slits, or slots, or slits and slots, orneither slits nor slots); and the means for coordinating may be providedwith a flat or bent or undulating curvilinear topography.

To configure the bi-sectional embodiment of the multi-sectional modularenergy absorber, the following steps are taken:

-   -   selecting a first section and a second section of one or more        energy absorbing units according to given spatial constraints        and desired energy absorbing criteria;    -   providing a means for coordinating energy absorbing units with a        pre-defined contoured topography;    -   locating one or more energy absorbing units in association with        the means for coordinating energy absorbing units so that the        one or more energy absorbing units are positioned in relation to        each other before, during and after relative motion between an        incident object and the energy absorber;    -   providing a wall within some or all of the sections in the one        or more energy absorbing units so that the wall provides an        upper perimeter, a lower perimeter, and an intermediate section        extending therebetween;    -   defining a number (m) of breaches within the wall of a        section, (m) being an integer selected from the group consisting        of (0, 1, 2, 3, . . . , 1000); and    -   providing a number (n) of apertures defined within the means for        coordinating energy absorbing units, (n) being an integer        selected from the group consisting of (0,1,2,3, . . . , 1000).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a bumper system including one embodimentof the modular energy absorber of the present invention;

FIG. 2 is a front elevational view of one module of a bi-section form ofenergy absorber;

FIG. 3 is a perspective view of a bi-section form of energy absorbingmodule depicting a number of breaches within the walls of a section insome energy absorbing units;

FIG. 4 is a rear perspective view of the embodiment of FIG. 3;

FIG. 5 is an end view thereof;

FIG. 6 is a top plan view of an energy absorber with three energyabsorbing modules, similar to that depicted in FIG. 1;

FIG. 7 illustrates one embodiment of a means for locating the sectionsof an energy absorbing unit in relation to each other;

FIG. 8 depicts an embodiment of a multi-sectional energy absorber inwhich energy absorbing units are placed in a staggered or alternatingsequence and in which a dome of an energy absorber is alternatelypositioned forwardly and rearwardly;

FIG. 9 is a perspective view of a bi-section embodiment of an energyabsorbing module in which two sections of the module appear as theymight emerge from a forming tool;

FIG. 10 depicts one form of a hinge region that unites two sections of abi-section energy absorbing unit;

FIG. 11 depicts a sectional view of an attachment area of the unit shownin FIG. 10 along a section between adjacent energy absorbing units;

FIG. 12 depicts a sectional view of the location and attachment areaalong a section between adjacent energy absorbing units;

FIG. 13 is a top view combining a multi-sectional modular energyabsorber with a bumper beam that lies inboard of the multi-sectionalenergy absorber;

FIG. 14 is a graph of force versus deflection for a conventionalthermoformed energy absorber and one constructed according to thepresent invention;

FIG. 15 is a force versus deflection curve comparing the proposedinvention to a foam energy absorber;

FIG. 16 is a side elevational view of an alternate embodiment of thepresent invention; and

FIG. 17 is a cross-sectional view of one energy absorbing unit of theembodiment of FIG. 16.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

1. The Energy Absorber

Turning first to FIG. 1 of the drawings, there is depicted amulti-sectional modular energy absorber 10 that has one or more energyabsorbing modules 15. The definition of the “energy absorbing module”which appears in the summary section of this application is incorporatedhere by reference. As depicted, the multi-sectional modular energyabsorber lies between an impact beam 11 and a bumper fascia 13.

As a frame of reference, the beam 11 is inboard (in relation to thevehicle center) of the multi-sectional modular energy absorber 10, whilethe bumper fascia 13 lies outboard thereof. Such is the case with afront bumper system. Corresponding positions describe a rear bumpersystem.

The modular energy absorber 10 is characterized by energy absorbingunits 12 that in one embodiment are connected by coordinating means 14so that they offer resistance and then buckle when impacted withsufficient force. Each module 15 includes means 24 (FIG. 2), such as abasal structure, for coordinating energy absorbing units 12 of a givenenergy absorbing module 15. The means for coordinating 24 has atopography that includes a number (n) of apertures 26 defined therein,where n is an integer ≧0. The apertures could be provided in the dome ofan energy absorbing unit. The topography may be planar, curved, orundulating to suit the spatial constraints of the application.

In a bi-sectional embodiment, at least some of the energy absorbingunits 12 are configured like a clamshell, as depicted in FIG. 9. A givenenergy absorbing unit 12 has a first section 14 and a second section 16.These sections 14, 16 are united to form a given energy absorbing unit12. In some embodiments, the sections are mirror images of each other.It should be appreciated that the size of the first section need not bethe same as the size of the second section. In some embodiments, thesections 14,16 are mirror images of each other. In other embodiments,they are not.

Preferably, means 18 for locating in relation to each other the sections14,16 are provided, as depicted in FIGS. 6 and 12. In one embodiment,the means for locating are represented by a female recess in one sectionand a male protuberance in another section. When the sections areunited, the respective location means fall into registration with eachother. The means for locating the sections also include the leaves 40,40′ of a living hinge 38 clips, rivets, conventional fasteners,adhesives, welding, pins, and combinations thereof.

Turning now to FIGS. 3 and 11, extending from at least some of the firstand second sections 14,16 are respectively first and second flangesections 20,22. When the clamshell-like bi-sectional modular energyabsorber is closed, the first flange of a given section mates with aflange of the second section. The means for locating the sections inrelation to each other are provided either by a hinge alone, or withinthe flange sections.

In one embodiment, the energy absorbing units 12 take the form oftruncated cones. The units are further characterized by certain shapes,dimensions, wall thickness, and material type that can be “tuned” usingnon-linear finite element analysis software to model a desired energyabsorber.

It will be appreciated that in a given application, a number of energyabsorbing modules 15 may be affixed to a substrate or supporting member,such as beam 11. In such cases, the beam 11 itself may serve as themeans 24 for coordinating energy absorbing unit and/or the means 18 forlocating them. The substrate helps to position and configure energyabsorbing modules to suit the needs of a particular bumper system.

As to be described in greater detail herein, the disclosed energyabsorbers preferably are made from polymers. Polyolefins offer the bestcombination of cost and performance. Specifically, these may includeBasell Polyolefins Pro-fax SV152 polypropylene copolymer and BPPetrochemicals 3045 polypropylene copolymer.

The energy absorbing units 12 coordinate with each other through theprovision of coordinating means 24 that position and support the unitsin relation to each other before, during and in some cases, afterrelative motion between an incident object (not shown) and themulti-sectional, modular energy absorber 10. That relative motion causesimpact between the energy absorbing units 12 and the incident object sothat forces resulting therefrom are at least partially absorbed. In thisway, the impact forces that are transmitted to a vehicle within which,for example, the multi-sectional modular energy absorber 10 is situated,are reduced. Also, the injuries sustained may be lessened.

As shown in FIGS. 3-5, at least some of the sections in an energyabsorbing units 12 include an upper extremity or perimeter 28, a lowerextremity or perimeter 30, and an intermediate section or wall 32extending therebetween.

Additionally, a number (m) of breaches 34 (FIG. 4) can be defined withina crushable unit 12 before impact. As used in this disclosure, the term“breaches” includes slits and slots. The term “slots” implies anaperture with facing edges which lacks material, or from which materialhas been removed. As used herein, the term “slits” implies a cut or gashthat is formed without the removal of material. In the preferredembodiment, the slots are inclined to an axis of symmetry 44 (FIG. 5) ofa given crushable unit 12 when the crushable unit 12 is presented in theform of a thermoformed cone.

As depicted in FIG. 2, the multi-sectional modular energy absorberincludes, in the embodiment depicted, a hinge region 38 having leaves40, 40′. It should be appreciated that in some embodiments, the hingeregion 38 may be lacking. In those embodiments, the individual sectionsof a given energy absorbing unit may merely interface with each otherwithout assistance from a hinge. In those embodiments that include ahinge region 38, each leaf 40, 40′ extends from one of the one or moresections 14, 16 so that the sections may be configured within thespatial constraints that are imposed by an environment within which themulti-sectional modular energy absorber 10 is positioned. Theenvironment (not depicted) is selected from a group consisting of aheadliner in a vehicle, a bumper assembly, a knee bolster, and a sideimpact location including a vehicle pillar, a door, an armrest, a headrest, a heel block, or seat back.

In one embodiment, the means for coordinating 24 the energy absorbingunits 12 takes the form of a web, a tether, a hinge, a planar surface(as depicted), rings, a supporting member, or a combination thereof. Insome cases, no apertures (n=0) are provided in the energy absorbingcoordinating means.

In FIG. 7, locating means 18 are provided between sections 14, 16 inorder to coordinate the deformation and energy absorbing characteristicsof adjacent sections. It will be appreciated that such means may takethe form of an adhesive, a clip, a vibration weld, an infrared weld, athermo-weld, a sonic weld, a heat stake, a “tongue in groove,” adovetail arrangement, and the like.

It will also be appreciated (FIG. 8) that the configurations depicted inFIGS. 2-7 may be configured such that adjacent energy absorbing units 12may be located in such a way that the periphery of the dome 42 of agiven unit 12 may be sized differently from that of the adjacent unit.

In some embodiments, the dome 42 or coordinating means 24 may have aconfiguration that is non-planar. For example, the dome 42 may undulateor be otherwise configured (either upwardly-convex or downwardlyconcave) in order to conform the multi-sectional modular energy absorber10 to the spatial constraints imposed by the environment in which theabsorber is installed.

It will be appreciated that as a result of “tuning” the energy absorber(e.g. dimensional control of wall height, provision of slits or slots orneither, wall thickness, and material selection), the configurationfollowing impact may, if desired, be located in substantially the sameor (usually) in a different or from the position as the pre-impactconfiguration.

In a given energy absorbing unit 12, where there are two sections, oneor each of the sections 14,16 are provided with an upper perimeter 28, alower perimeter 30, and an intermediate wall 32. In the wall 32, theremay be a number (n) of breaches defined before impact, where n is aninteger ≧0. The intermediate wall 32 at least partially collapses duringenergy absorption. In general, if desired, the multi-sectional modularenergy absorber 10 can be configured so that the wall 32 cansubstantially recover to its undeflected condition after impact.

As indicated in FIG. 5, at least some of the energy absorbing units 12are oriented such that intermediate walls 32 are inclined to a majorincident component 36 of the impacting force. It should be appreciated,however, that the term “inclined” may alternatively include an angle ofinclination which is zero or 180°. Some of the energy absorbing units 12cooperate with the means for coordinating 24 to afford mutual support indecelerating an object that imparts the impacting force.

While the coordinating means may be located at an intermediate sectionof a wall 32, it will be appreciated that it may also lie proximate itstop or bottom edges 28,30.

It will be appreciated that the wall 32 can be characterized by athickness (t) which may or may not be uniform between a top edge 28 anda lower edge 30 of the wall 32. In some configurations, where particularenergy absorbing characteristics are desired or mandated, the wall 32 ofa given energy absorbing unit 12 may have an average thickness (t₁) thatdiffers from an average thickness (t₂) of a wall associated with anotherenergy absorbing unit. Similarly for dome thickness.

In some embodiments (FIG. 4, for example), the means for coordinating 24may include one or more ribs or troughs or channels. Optionally, theribs may be provided so that stiffness results in one direction, versusflexibility in another direction. This affords additional latitude tothe designer who may wish to confer stiffness in one direction forimpact resistance, yet flexibility in another direction to enable agiven energy absorbing module to bend or conform to the spatialconstraints imposed by the environment in which the energy absorber isinstalled. One example is depicted in FIG. 6. In that figure, stiffnessis provided in the plane of the paper, while flexibility is providedabout an axis that is perpendicular to the paper.

The lower perimeter 30 of a given energy absorbing unit 12 may, forexample, describe a circle, an oval, an oblate oblong, a polygon, or anellipse. Similarly for the upper perimeter 28 and an intermediatesection of wall 32. Combinations of such shapes among adjacent energyabsorbing units are deemed within the scope of the invention.

Where thermoforming is the manufacturing method of choice, slits arepreferred because there is no requirement to remove slugs of unwantedmaterial. It will be appreciated that slots tend to weaken the energyabsorbing structure, other things being equal, while reducing the weightof the energy absorbing unit.

It will be apparent that in many applications, the multi-sectionalenergy absorber 10 may perform satisfactorily in an inverted position.

Thus far in this disclosure, there has been described a bi-sectionenergy absorbing unit. It will be appreciated that the multi-sectionalenergy absorbing unit may alternatively include one section which iscomplimented by one or more sections, so that the energy absorbing unitmay include two, three, four, or more sections. This may be desirable inthose applications where a given energy absorbing unit may require itsenergy absorbing characteristics to be finely tuned. In such embodimentsof the multi-section energy absorbing unit, flange sections 20, 22 mayor may not be provided. Similarly, for hinge regions 38. In someapplications, the multi-sectional energy absorbing unit may be locatedon a supporting member such as an impact beam 11, or a highway guardrail, a barrier wall, or the like. For example, the sections could besupported by one or more arcuate grooves provided in the supportingmember.

FIGS. 16-17 depict an energy absorbing unit 12 wherein an intermediatewall includes stepped portions 49 that include interconnecting sections48. Preferably, the step portions 49 have a lesser thickness closer tothe dome 42 than at the means for coordinating 24. This tends to providecollapse characteristics wherein the stepped portion proximate the dome42 collapses in response to a force applied before a step portion 49that is closer to the means for coordinating 24.

If desired, the interconnecting sections 48 may likewise be tapered,inclined to an axis of symmetry, and be in some embodiments thinnercloser to the dome 42. This tends to provide a preferential collapseregimen wherein sections closer to the dome 42 collapse before thosecloser to the means for coordinating 24.

It will be appreciated that the interconnections 48 need not lie in anhorizontal plane, but instead may be oriented at an inclination thereto.

In some embodiments, a designer may decide to nest or stack one or moreenergy absorbing modules. The scope of the claimed invention isexpressly contemplated to comprehend such configurations.

2. The Design Method

To address the problem of thinning, the designer now has the ability tomold a clamshell-like multi-sectional modular energy absorber in a tool.The intermediate part as it leaves the tool resembles that as depictedin FIG. 9. Problems of excessive thinning and non-uniformity ofthickness distribution are minimized.

The designer now has the latitude to call for energy absorbing unitshaving intermediate walls 32 which are significantly higher or tallerthan by following conventional practices.

One method for configuring a multi-sectional modular energy absorbercomprises the steps of:

selecting one or more energy absorbing units having multiple sections,according to given spatial constraints and desired energy absorbingcriteria;

providing a means for coordinating energy absorbing units with apre-defined contoured topography;

locating one or more energy absorbing units in association with themeans for coordinating energy absorbing units so that the one or moreenergy absorbing units are positioned in relation to each other before,during and after relative motion between an incident object and theenergy absorber;

providing a wall within some of the one or more energy absorbing unitsso that the wall provides an upper perimeter, a lower perimeter, and anintermediate section extending therebetween;

defining a number (m) of breaches within the wall, (m) being an integerselected from the group consisting of (0, 1, 2, 3, . . . , 1000);

providing a number (n) of apertures defined within the means forcoordinating energy absorbing units, (n) being an integer selected fromthe group consisting of (0, 1, 2, 3, . . . 1000);

quantifying the resulting modular energy absorbing characteristics ofthe absorbing structure;

comparing the characteristics with those desired; and

reiterating as necessary.

3. The Manufacturing Method

The manufacturing method contemplated by the present invention canusefully be deployed where the height of the energy absorbing unit 12exceeds about 50 millimeters. The invention, is not however, limited toabsorbers that are so dimensioned. By using a manufacturing method thatcalls, for example, for the preparation of a clamshell-likemulti-sectional energy absorber, energy absorbing units can bemanufactured which are tall, or short, or intermediately sized,depending upon the designer's preference.

An absorber's crush resistance be “tuned” or “dialed up or down” toprovide the greatest measure of energy management or the highest levelof vehicle or occupant protection for a given set of impact conditions.Foam energy absorbers can be tuned by a change in density, but haveproven to be less efficient than those composed of metal, thermoplastic,or composite materials (see, e.g. FIG. 15). Metal and compositeabsorbers are proven to be more expensive than their plasticcounterparts, such as injection molded and thermoformed energyabsorbers.

Slits (no material removed), or slots (areas devoid of material) may beprovided which run mostly parallel to an axis of symmetry of a givenenergy absorbing unit. Such breaches may or may not be present, but whenpresent, the slots may or may not be of varying width. As discussedearlier, ribs that protrude from the interior or exterior of a wall ofan energy absorbing unit may or may not be present.

The presence of breaches, such as slits, or slots reduces the crushresistance of a given energy absorbing unit. The number of slits 34 canalso be changed to optimize impact performance to a lesser degree.Preferably, but not necessarily, the slits should run the entire lengthof the wall 32.

In summary, the crush resistance of each recess can be varied in orderto optimize the impact performance with a minimal impact on toolingcost. It also lends itself to high manufacturing rates and low costsversus current competitive products, while still providing excellentimpact performance.

4. Experimental Observations

Experiments have been performed to observe the resistancecharacteristics of a given absorber design and efficiently tune oroptimize its geometry to match known benchmarks (up to 80 psi) of givencountermeasures.

FIGS. 14-15 are force versus deflection curves. FIG. 14 includes twocurves: the lower curve reflects the performance of current thermoformedenergy absorbers. The upper curve depicts the energy absorbingperformance of a structure made according to the present invention.

Noteworthy is that the inventive energy absorber (upper curve) has ayield point that is about 3.9 times higher than standard thermoformedenergy absorber. As used herein the term “yield point” connotes a forcethat the part will take before it plastically deforms—i.e. the firstpoint where the curve goes from vertical to horizontal. Noteworthy alsois that the inventive energy absorber has an energy absorption that isabout 1.8 times greater than standard thermoformed cones. Energyabsorption is represented by the area under the curve.

FIG. 15 is a force versus deflection set of observations that comparethe inventive energy absorbers (lower curve) to EPP bumper foam. Theinvention has an 18% greater deflection than the foam when the force is35 kN.

An equation commonly used to calculate energy absorbing efficiency is:${{EA}\quad{Efficiency}} = \frac{\left( {{Area}\quad{under}\quad F\text{-}D\quad{Curve}} \right)}{\left( {{Rectangular}\quad{area}\quad{with}\quad{same}\quad{maximum}\quad F\quad{and}\quad D} \right)}$Applying this equation, the invention (FIG. 15) also has an energyabsorbing efficiency of 65% while that of the foam is 51%.

Experimental observations reveal that the resistance characteristics ofthe energy absorbing units are most sensitive to the number of slits orslots and wall thickness. The mean pressure exerted by an energyabsorbing module in response to an impacting force can also be tuned byadjusting the spacing between energy absorbing units within practicalmanufacturing and performance limits. One can therefore optimize theresistance pressure of the module for a given set of impact conditionsby changing the design of the units and their spatial orientation withinthe module.

While embodiments of the invention have been illustrated and described,it is not intended that these embodiments illustrate and describe allpossible forms of the invention. Rather, the words used in thespecification are words of description rather than limitation, and it isunderstood that various changes may be made without departing from thespirit and scope of the invention.

1. A multi-sectional, modular energy absorber comprising: one or moremodules, one or more of which having: one or more energy absorbingunits, at least some of which have a first section and a second sectionthat are united to form an energy absorbing unit; a first and secondflange section extending from at least some of the first and secondsections; means for locating the sections in relation to each other;means for coordinating energy absorbing units in at least one of the oneor more modules, the means for coordinating having a topographyincluding a number (n) of apertures defined therein, where n is aninteger ≧0, the means for coordinating positioning the one or moreenergy absorbing units in relation to each other before, during andafter relative motion between an incident object and the modular energyabsorber, so that impact forces resulting therefrom are at leastpartially absorbed by the energy absorbing units, at least some of thesections including an upper perimeter, a lower perimeter and anintermediate wall extending therebetween with a number (m) of breachesdefined in the intermediate wall before impact, where m is an integer≧0, the wall at least partially collapsing during energy absorption;wherein at least some of the energy absorbing units are oriented suchthat their intermediate walls are inclined to a major incident componentof the impacting force, and wherein some of the energy absorbing unitscooperate with the means for coordinating to afford mutual support indecelerating an object that imparts the impacting force.
 2. The modularenergy absorber assembly of claim 1 further including: a hinge regionwith leaves positioned between the first and second sections, at leastsome of the first and second sections being provided with a dome, eachleaf extending from one of the domes.
 3. The modular energy absorber ofclaim 1 wherein the number (n) of apertures equals zero.
 4. The modularenergy absorber of claim 1 wherein the means for coordinating comprisesa form selected from the group consisting of a web, a tether, a hinge, aplanar surface, a rib, a channel, a non-planar surface, and combinationsthereof.
 5. The modular energy absorber of claim 2 wherein the dome hasa configuration that is non-planar.
 6. The modular energy absorber ofclaim 1, wherein some of the one or more energy absorbing units have animaginary axis of symmetry and at least a segment of the dome isinclined to the axis of symmetry.
 7. The modular energy absorber ofclaim 1 wherein a released configuration following rebound is located insubstantially the same position as a pre-impact undeflectedconfiguration.
 8. The modular energy absorber of claim 1 wherein theintermediate wall has a thickness, the thickness being non-uniformbetween the upper and lower perimeters.
 9. The modular energy absorberof claim 1, wherein the intermediate wall of a given energy absorbingunit has an average thickness (t₁) that differs from an averagethickness (t₂) of a wall associated with another energy absorbing unit.10. The modular energy absorber of claim 1, wherein a lower perimeter ofan energy absorbing unit defines a geometric figure that is selectedfrom the group consisting of a portion of a circle, an oval, an oblong,an oblate oblong, an ellipse, and a polygon.
 11. The modular energyabsorber of claim 1, wherein an upper perimeter of an energy absorbingunit defines a geometric figure that is selected from the groupconsisting of a circle, an oval, an oblong, an oblate oblong, anellipse, and a polygon.
 12. The modular energy absorber of claim 1,wherein the size of the first section differs from that of the secondsection.
 13. The modular energy absorber of claim 1, further includingone or more stiffening ribs that are provided to one or more of thesections.
 14. The modular energy absorber of claim 1, where at leastsome of the breaches comprise slots, the slots having edges.
 15. Themodular energy absorber of claim 1 wherein the number (m) of breachesequals zero.
 16. A multi-sectional, modular energy absorber comprising:one or more modules, one or more of which having: one or more energyabsorbing units, at least some of which have a first section and atleast one other section that are united to form an energy absorbingunit; a first and second flange section extending from at least some ofthe sections; means for locating the sections in relation to each other;means for coordinating energy absorbing units in one of the one or moremodules, the means for coordinating having a topography including anumber (n) of apertures defined therein, where n is an integer ≧0, themeans for coordinating positioning the one or more energy absorbingunits in relation to each other before, during and after relative motionbetween an incident object and the modular energy absorber, so thatimpact forces resulting therefrom are at least partially absorbed by theenergy absorbing units, at least some of the sections including an upperperimeter, a lower perimeter and an intermediate wall extendingtherebetween with a number (m) of breaches defined in the intermediatewall before impact, where m is an integer ≧0, the wall at leastpartially collapsing during energy absorption; wherein at least some ofthe energy absorbing units are oriented such that their intermediatewalls are inclined to a major incident component of the impacting force,and wherein some of the energy absorbing units cooperate with the meansfor coordinating to afford mutual support in decelerating an object thatimparts the impacting force.
 17. The modular energy absorber assembly ofclaim 16 further including: at least one hinge region, at least one ofthe regions having leaves positioned between the two sections; at leastsome of the sections being provided with a dome, at least one leafextending from one of the domes.
 18. The modular energy absorber ofclaim 16 wherein the number (n) of apertures equals zero.
 19. Themodular energy absorber of claim 16 wherein the means for coordinatingcomprises a form selected from the group consisting of a web, a tether,a hinge, a planar surface, a rib, a channel, a non-planar surface, andcombinations thereof.
 20. The modular energy absorber of claim 17wherein the dome has a configuration that is non-planar.
 21. The modularenergy absorber of claim 17 wherein some of the one or more energyabsorbing units have an imaginary axis of symmetry and at least asegment of the dome is inclined to the axis of symmetry.
 22. The modularenergy absorber of claim 16 wherein a released configuration followingrebound is located in substantially the same position as a pre-impactundeflected configuration.
 23. The modular energy absorber of claim 16wherein the intermediate wall has a thickness, the thickness beingnon-uniform between the upper and lower perimeters.
 24. The modularenergy absorber of claim 16, wherein the intermediate wall of a givenenergy absorbing unit has an average thickness (t₁) that differs from anaverage thickness (t₂) of a wall associated with another energyabsorbing unit.
 25. The modular energy absorber of claim 16 wherein alower perimeter of an energy absorbing unit defines a geometric figurethat is selected from the group consisting of a portion of a circle, anoval, an oblong, an oblate oblong, an ellipse, and a polygon.
 26. Themodular energy absorber of claim 16 wherein an upper perimeter of anenergy absorbing unit defines a geometric figure that is selected fromthe group consisting of a circle, an oval, an oblong, an oblate oblong,an ellipse, and a polygon.
 27. The modular energy absorber of claim 16wherein the size of the first section differs from that of at least someof the at least one other sections.
 28. The modular energy absorber ofclaim 16 further including one or more stiffening ribs that are providedto one or more of the sections.
 29. The modular energy absorber of claim16 where the breaches include slots, the slots having edges that are notparallel.
 30. The modular energy absorber of claim 16 wherein the number(m) of breaches equals zero.
 31. The modular energy absorber of claim 16further including means for attaching one or more modules of themulti-sectional modular energy absorber to a bumper beam, the means forattaching being selected from the group consisting of adhesives, pushpins, formed snaps, dovetails, rivets, and combinations thereof.
 32. Themodular energy absorber of claim 16 wherein the intermediate wallextending between the upper and lower perimeter of one or more energyabsorbing units includes one or more stepped portions that are linked byinterconnecting sections.
 33. The modular energy absorber of claim 32wherein the stepped portions have a thickness that is greater than thethickness of those in proximity to the upper perimeter.
 34. The modularenergy absorber of claim 32 wherein the interconnecting portions have ataper such that the thickness of the interconnecting portions rises withdistance from an axis of symmetry.